Authors

Abstract

This paper introduces a mathematical model to calculate the amount of tool
inclination angle in turning operation depending on controlling the chip flow along the
cutting edge, and to simplify the setting of this angle and the direct relation with nose
setting distance, a model is achieved to calculate the setting nose distance instead of
changing the inclination angle. Results conducted on a series of experiments by
changing tool nose setting distance where most of the cutting conditions kept constant,
except tool nose setting below and above the workpiece centre, and its effect of
obtained surface roughness was measured at each step.
Theoretical results for finishing turning operation, for depth of cut less than 1
mm, show that setting tool nose below the workpiece centre will be similar to that of
setting positive angle of inclination.
The main function of the derived model of the inclination angle is to make
equal chip flow along the cutting edge and the chip will be cured far enough from the
machined surface and therefore eliminate the chip and hence improve the workpiece
surface roughness.
The proposed theoretical model proved that in external turning with finishing
operation the suggested inclination angle (λ) must have positive values, and the setting
distance has a negative value. While in the experimental work, the workpiece surface
finish has been improved when setting distance has negative value below the
workpiece centre.

Keywords